Anal Fissure is a tear in the anal skin which can extend into the anal canal. A fissure is typically extremely painful and can be associated with bleeding during bowel movements. Although fissures are common, people usually get them confused with hemorrhoids.
Anal fissures can develop at any point of age and can happen to both males and females. Majority (85 to 90%) of anal fissures occur in the back midline position of the anus as it is the weakest part of the anal skin. Those who have multiple fissures or fissures located in unusual locations may have an underlying disease (eg. Crohn’s disease).
Pain and bleeding are the most common symptoms of a fissure. The patient classically experiences severe pain (sometimes described as passing glass shards) during the bowel movement along with some bleeding. The pain may last for a minute to several hours.
What Causes Fissures?
Usually, using excessive force (straining) at stools, accompanied by a hard bowel movement is responsible for the fissure. Occasionally excessive trauma from repeated bowel movements like diarrhoea and loose stools can also cause it.
The pain results in tightening of the anal sphincter (spasm) which causes an increase in sphincter pressure. More effort is needed for bowel movements which can cause more straining and tearing. This consequently sets up a vicious cycle, which results in more tightening and reduces the blood flow to the injured area which slows healing.
Commonly, patients may be misdiagnosed as having hemorrhoids because both have common symptoms. But these are 2 entirely different conditions requiring different treatments. As such, it is important to seek the right attention early in order to get the right treatment.
An acute fissure has the appearance of a simple tear in the anus skin, but after 6 to 8 weeks it becomes chronic and may cause swelling and scarring and an external lump along called a sentinel pile.
The principle of treatment is to break the cycle of pain and spasms, so as to allow healing of the fissure.
If it is acute, surgery may be avoided. The most effective treatment for acute anal fissure is the use of GTN ointment to relax the anal muscle and relieve spasms. At the same time, stool softeners are prescribed to minimize trauma during bowel movements.
However, once it shows signs of chronicity (scarring and sentinel pile) or having failed the above treatment, an effective surgical technique is the Lateral Anal Sphincterotomy. In this technique, a small amount is divided in a controlled manner under anaesthesia to promote fissure healing. Occasionally, especially for chronic or recurrent fissures, botox injection may be useful.